This invention relates to packing trays and, more particularly, to polystyrene foam trays for packing fruit, and other fragile objects.
In the prior art, two basic types of tray packaging have been developed that are commonly used to package fruit, and other fragile objects, such as light bulbs: tray packs and cell packs. (To illustrate the invention, reference herein is made to fruit; other fragile objects can be packed in similar fashion). First, xe2x80x9ctray packsxe2x80x9d are single stacked trays in which fruit is accommodated. The cells of the tray packs are relatively shallow to maximize the number of cells per unit area formed on a tray.
A tray pack that is commonly found in the prior art is embodied in U.S. Pat. No. 3,040,923 to Leitzel, which was issued on Jun. 26, 1962 and is entitled xe2x80x9cMOLDED PULP PACKING TRAYxe2x80x9d. The Leitzel tray is representative of a typical prior art design and is formed with a plurality of cells, wherein sinuous ridges are formed to separate the cells in a transverse direction, while flat planar portions are used to separate the cells in longitudinal directions. The crests of the sinuous ridges are formed to be higher than the planar portions and to be generally coplanar with the edge of the tray. When stacked, the planar portions of an upper tray bear against fruit packaged in a lower tray. To minimize bruising of the fruit, U.S. Pat. No. 3,040,923 states that contact between packaged fruit and the external surfaces of the cells of an upper tray are not desired. Therefore, it is intended that the planar portions solely bear against the fruit of a lower tray.
U.S. Pat. No. 3,962,469 to Leavens et al. which was issued on Jun. 8, 1976 and is entitled xe2x80x9cFRUIT TRAY PACKAGExe2x80x9d discloses a fruit tray package arrangement which uses the tray pack disclosed in U.S. Pat. No. 3,040,923. Here, however, it is noted that the Leitzel tray has a shortcoming, wherein a smaller piece of fruit, which is not sufficiently large enough to come into bearing engagement with the associated planar portion of an upper stacked tray, is free to shift about the cell and may be damaged during shipping. To overcome this deficiency, Leavens et al. discloses using a plastic film envelope about each tray which is intended to provide a downward bearing force against each piece of packaged fruit, taking into account variations in size.
Second, xe2x80x9ccell packsxe2x80x9d have been used in the prior art wherein a pair of cooperating trays is disposed in facing relationship to define the cell pack, with fruit being wholly encapsulated between vertically aligned cells of the upper tray and the lower tray. An example of a cell pack is disclosed in U.S. Pat. No. 1,477,921 to Thompson which was issued on Dec. 18, 1923 and is entitled xe2x80x9cFRUIT CARRIERxe2x80x9d.
For transportation and/or storage, packaged cell packs are stacked in cases, or other transportation and/or storage units, often with the cells of all of the cell packs being vertically aligned. Thus, the packaged and stacked cell packs typically do not have any portions in nesting interengagement (i.e., the height of n number of stacked and packaged cell packs is equal to the sum of the individual heights of the packaged cell packs). Alternatively, the Thompson cell pack is made in two variations to allow for nesting, wherein the two variations of cell pack are alternated in a stacked arrangement.
Tray packs are packaged and stacked in cases with cells of an upper-stacked tray being nested between the packaged fruit of a lower-stacked tray (i.e., the height of n number of stacked and packaged tray packs is less than the sum of the individual heights of the packaged tray packs). In similar vein to the Thompson cell pack, some tray pack designs are formed in two variations to allow for efficient stacking within the same container. The two designs have different cell arrangements to allow for efficient nesting, yet the tray packs may be stacked within a rectangular cross-sectional container with the edges of the stacked trays being in registration.
It is an object of the subject invention to provide a packing tray suitable for use both in a tray pack arrangement and in a cell pack arrangement.
It is also an object of the subject invention to provide a packing tray which provides sufficient protection from external hazards, yet is sufficiently versatile to accommodate fragile objects, including fruit, of different sizes, and in different packing orientations.
The aforementioned objects of the subject invention are met by a packing tray preferably formed from a sheet of polystyrene foam which is molded into a cellular structure. The cellular structure includes longitudinal rows of cells, wherein alternating rows include odd and even numbers of cells. Preferably, the even number rows include one more cell than the odd number rows. For example, a first row may have six cells, an adjacent row five cells, the following row six cells, and so forth. The cells are arranged so that the centers of even number rows and odd number rows are respectively centered relative to one another. In addition, the centers of the cells of the odd number rows are interposed between the cells of even number rows, and preferably aligned to be centrally disposed between the even number cells.
The packing tray is further formed with a peripheral edge which defines a reference plane. Within the packing tray, and bounded by the peripheral edge, is a network of cell dividers which at least partially separate the respective cells. The cell dividers are generally saddle-shaped in cross-section and formed to blend between adjacent cells. Also, posts are located at junctures of cell dividers. It is preferred that the top surfaces of the posts be generally coplanar with the reference plane defined by the peripheral edge, whereas, at least major portions of the cell dividers be recessed below the reference plane. In this manner, the packing tray has a peripheral edge which provides protection for packaged fruit from external forces, yet the tray has relatively low cell dividers which provide versatility in the size of the objects to be packaged, as well as the packaging orientation of the objects, whether being horizontal, vertical, or oblique.
With the cellular structure described above, the packing tray of the subject invention can be used in a tray pack application where trays can be reversed end-to-end and stacked upon one another. In contrast to the manner of packing the prior art Leitzel tray, fruit, or other objects, packed with the tray of the subject invention will preferably simultaneously bear against the exterior surfaces of at least two cells of an upper-stacked tray. The simultaneous engagement against the upper cells limits the relative movement of the fruit, or object, and prevents bruising thereof. Due to the forgiveness of the constituent foam material of the packing tray, and the smooth outer surfaces of the cells, it has been found that the bearing engagement of the cells against the fruit is acceptable and does not result in excessive bruising, or other damage. The Leitzel tray is formed from molded pulp which does not define smooth outer surfaces, and the inherent forgiveness of the material is much more limited than that of polystyrene foam.
Additionally, the packing tray of the subject invention can be used in a cell pack arrangement, wherein two of the packing trays can be placed in facing relationship to encapsulate fruit or other objects. The cell dividers and the posts provide for separation between adjacent packed objects. In addition, the increased heights of the peripheral edges of the two packing trays from the respective cell divider networks cause the peripheral edges to depend over substantial portions of the peripheries of the cell pack to provide a buffer against external forces while in a cell pack arrangementxe2x80x94it should be noted that it is preferred that the peripheral edges do not contact. If the depths of the cells were to be increased so as to enable abutting contact between the peripheral edges of the two trays in a cell pack arrangement (as in the prior art), the number of cells the packing trays could accommodate would be limited. To achieve the highest economy of a tray, the greatest number of cells per unit area is to be provided. The subject invention achieves this objective by having the peripheral edges be spaced apart in a cell pack arrangement (in contrast to the prior art), without sacrificing the amount of protection afforded packaged objects.
These and other features of the invention will be better understood through a study of the following detailed description and accompanying drawings.